Nothing is more irritating than people who do not keep _______ t

Nothing is more irritating than people who do not keep _______ the point.
A、on
B、up
C、along
D、to
【正确答案】：D
【题目解析】：keep on doing sth/sth 继续做… keep up 保持，不落后，keep along 沿着…继续 keep to 固守 坚守（习惯） 固定搭配 keep to the point 切题，紧扣主题。原句意思为：没有什么比讲话不扣主题更令人恼火了。